Strawberry plant called `X13`

ABSTRACT

This invention relates to a new distinct short day winter-planted variety of strawberry plant named `X13`. The plant of this variety is distinguished by its dark, glossy foliage and its ability to initiate flowers from early spring to late fall in the Central Coast of California and spring and summer in southern California. The fruit is distinguished by its consistently high flavor, long shelf life, good fruit color inside and out and glossy, smooth surface. Its fruit is adapted to being processed for the freezer trade, especially for the Individual Quck Frozen berry demand, as well as for the fresh market.

DESCRIPTION

This invention relates to a new distinct short day winter-plantedspring-bearing variety of strawberry plant identified and designated as`X13` which is a result of a cross of the unpatented variety known asDriscoll Strawberry Associates, Inc. (DSA) selection Z2 and the `JoeReiter` U.S. Plant Pat. No. 5,300. The variety is botanically identifiedas F.×ananassa Duch.

The seedlings resulting from the aforementioned cross were multiplied bystolon runners in Shasta County in a propagating nursery and otherrunner plants of each seedling clone were taken for testing to fruitingbeds on the property of DSA. The runners from clones of the seedlingheld in Shasta County propagating nursery were set for further testingon the property of DSA. These tests indicated the merits of `X13` andresulted in its selection as a promising test variety. Subsequent testson DSA's Fly Ranch land proved that the variety had commercial value inCalifornia.

In the Drawing

FIG. 1 shows the plant parts of the new variety, typical in size, shapeand color. The berry in cross section, illustrates flesh color andcharacteristic core cavity. The inflorescene illustrates typicalbranching and relative size during the middle of June.

The illustration shows two pedicels holding secondary berries and apedicel holding one tertiary berry, and this is typical even as late asSeptember. The primary berry may be wedge in shape with somelongitudinal ribbing, but the symmetrical smooth conic berry in theillustration is typical as is the heavy shoulders with the calyxclasping the shoulders. The surface color is uniform over the entiresurface and this is truce early in the year in contrast to the variety`Chandler`, U.S. Plant Pat. No. 5,262, whose shoulders are light incolor when grown in southern California early in the spring. The petioleis typical and shows a bract present, but bracts are not always present.The flowers and calyx are typical with anthers producing an abundance ofpollen.

The novel plant of `X13` has wide adaptability having commercial valueboth in southern California and the central coast of California.

The plant of `X13`, in southern California is slightly smaller in sizeand darker in color than the `Joe Reiter`, U.S. Plant Pat. No. 5,300, inearly spring, but will approach it in size by June and July. Its crowncrop, the crop initiated at the nursery, is usually equal to the `JoeReiter` in earliness and production to the first of April, but its fruitsize is not as large (see Table #1). One of its main attributes is itsconsistent good flavor which is as good as `Joe Reiter` (Tables #2 and3). This production is dependent on the fact that the variety is dugduring October at a high elevation nursery where the proper chilling hasoccurred and is planted at the correct time.

Table #1 lists digging and planting dates and the production (Bon is ahigh-elevation nursery). Refractometer readings in Oxnard, Calif. duringMarch gave `X13` a rating of 9.9% soluble solids and `Joe Reiter` 10.4%.Both of these ratings are considered high. Its other strong attribute isits fruit color inside and out and its outstanding shelf life due to itsfirm flesh and skin, as well as its attractive high gloss. In the oxnarddistrict of southern California, it is capable of producing between June27 and July 8, 560 grams per plant of superior quality fruit for theprocessing market. Its fruit character after being frozen has been ratedhigh and it is especially attractive with good dessert qualities whenfrozen for individual quck frozen, I.Q.F. (the berries are frozen andmarketed without being sliced).

`X13` is also distinguished from `Joe Reiter` in southern California inthat during March, individual central leaflets are not as long or aswide as `Joe Reiter`, and individual serrations are more acute at theirapex than `Joe Reiter`.

The fruit appearance is darker, has firmer skin and its shape doesn'tbecome globular and rounded at the tips during the late spring crop asdoes `Joe Reiter`. The isozymes in leaf extract vary from `Joe Reiter`in that the PGI of `Joe Reiter` is A4 and `X13` is A2 (see Table #5). Itdistinguishes itself from the `Chandler` variety in southern Californiain that its plant and crop is later to develop and mature, its plant andleaflets are darker, its fruit is more uniform in color at maturity, itsfruit surface is smoother and its flavor rates are superior (See Table#2).

In the central coast regions of California, even though `X13` is a shortday plant (not an everbearer), it has the ability to crop from Aprilthrough October if the plant receives the correct chillign (as describedabove) before being planted. Table 190 4 gives the production by themonth and year-end total as compared to the variety `Swede` (DSA varietyU.S. Plant Pat. No. 6,191). Its petioles are longer than `Swede` (seeTable #6). The plant size is larger than `Swede` in September (see Table#7). Individual leaflets are similar in size and leaflet serrations aresimilar in depth to `Swede` (see Table #6), but individual serrationsare sharper (not as rounded) at their apex as are `Swede's`. When giventhe same chilling before being planted, `X13` produces more runners perplant than does `Swede`. The total length of the inflorescence of `X13`is longer than `Swede` and thus produces its fruit for picking furtherfrom the crown than does `Swede`. The average fruit size for thefruiting season is not as large as `Swede`, as there is a drop in sizebetween the primary and secondary berries of the new variety. Primariesof the new variety can be large, as large as `Swede`, especially duringthe fall crop. Individual berries are firmer than `Swede`, and lessprone to color unevenly around and shoulders. Both varieties haveattractive berries with heavy shoulders and are conic to wedge in shape.The fruit of `X13` is not as prone to produce short wedged fruit orfolded, seedy split tips as does `Swede` in the spring. Both varieties,however, produce an abundance of pollen even early in the spring. Bothvarieties have outstanding flavors and panels have rated them equal (seeTable #3). One of the distinguishing differences in the two varieties isthat the hair on pedicels of `Swede` is perpendicular to the pedicelwhile `X13` is irregularly parallel to the pedicel.

Tests have shown `X13` to be susceptible to verticillium wilt, andangular leaf spot. Its fruit is susceptible to the anthracnose pathogencolletotrichum, but its plants show some tolerance. It has not beentested against phytophthora pathogens and it has not shown to besusceptible to the natural invasions of strawberry viruses common to thefruiting bed of California. It has not shown damage symptoms from pwderymildew in the fruiting beds or in the nursery production increase plots.It has not been noticeably sensitive to the two-spotted mitsinfestations of California.

The varietal characteristics of the novel plant, described below indetail, were observed mainly during March, April and May in Oxnard(southern Calif.), and June and September in Watsonville (centralCalif.). Both areas are coastal regions near the Pacific ocean. Thecolor terminology is in accordance with the Munsell Color System.

SPECIFIC DESCRIPTION

Plant: Small and dark during early March in Oxnard, even when givennecesssary chilling, but becoming larger during the fruiting season.Becoming large in Watsonville (see Table #7), often developing seven toeight crowns by end of the fruiting season. Considered a moderately highchilling variety requiring a moderate amount of chilling before beingplanted.

Leaves: The central leaflet, mostly medium in size in Oxnard duringApril, averaging 5.5 cm in width and 6 cm in length, but becoming largerin Watsonville during September, averaging 6.3 cm in width and 7.0 inlength. Leaflets mostly held on the plant parallel to the soil surface.Serrations are moderately deep (see Table #6). It is common to havesmall double serrations present at the point werhe serrations join. Theapex of serrations do become pointed, not rounded. Color of upper sideof leaf in oxnard during March is 2.8G-2.0/4.4 and 1.5G-2.8/74 inSeptemeber in Watsonville and the underside is 2.5 GY 4.3/7.1 inWatsonville. Petioles are short in Oxnard in March ranging from 10 to 13cm (measuring from the bract that joins the crown to the petiolule) andincreasing in length during the season and averaging 19 cm in length inWatsonville during September. Some bracts develop from the petioles.During periods, portions of the petioles may become purple. Thispurpling does not seem related to any pathogen and to the time thisapplication is submitted these purple areas have not been detrimental tothe plant growth. Petiolules of the central leaflet become long duringSeptember, October, Often over 20 mm, but averaging 10 mm. Table #5gives the isozyme banding patterns compared to the `Swede`, `Commander`and `Joe Reiter` varieties.

Runners: Runners are vigorous and abundant at the nursery and excessiveamounts can be produced at the fruiting bed if the plant is given morethan adequate chilling before being planted.

Inflorescence: Crown crop inflorescences are medium in length, 18 cm,and by May in Oxnard, the average is 25 cm (measuring total length fromthe crown to extension of ripe berries). In Watsonville, by September,the total length average is 28.9 cm. The common peduncle is short inMarch in Oxnard, 4.5 cm in length, but increases to 14.6 cm average bySeptember in Watsonville. The pedicel holding primary berries averages 8cm and may be longer than this during the crown crop. The diameters ofthese pedicels vary from 2 to 3 mm. The pedicel holding primary berriesmay originate from the axil of two secondary peduncles or from one ofthe secondary peduncles. Pedicels holding secondary and tertiary berriesare often fused together. A typical inflorescence contains a primary,two secondaries and one or two tertiaries. There is a noticeable drop insize between primary and secondary berries. The hair on pedicles isirregularly parallel to the pedicel. The flowers produce anthers with anabundance of pollen even during February in southern California. Petalsfrom primary flowers average 5.9 in number and the average diameter ofpistils of these flowers is 7.4 mm in diameter during September inWatsonville.

Fruit: The fruit surface is noticeably smooth, but the crown crop inmarch and the late September crop produces some ribbing and wedged fruitin outline with the length less than the width. During much of the crop,however, the primaries, secondaries and tertiaries produc symmetricalconic fruit. The short to medium wedged fruit (described in the USDABulletin 1043) has heavy shoulders with the calyx joining the fruit at apoint within the outline of the fruit, so that sepals are unable toclasp the berry. Even symmetrical conic fruit has heavy shoulders,rarely necked. The surface is smooth with the seed slightly exerted toeven with the surface. Ripe berries are uniform in color and have a goodgloss. The flavor is consistently good (see Tables #2 and 3). There is anoticeable drop in size between primary and secondary fruit which oftendetracts from the fresh market appearance. The size of primary berriesin Oxnard during March averages 46 mm in length and 40 mm in width. InWatsonville, during mid-summer, the size is less than in the spring, butin September and October, primary fruit size increases to an average of43 mm in length and 42 mm in width. During this total production period,both the skin and flesh remain firm, giving the fruit an excellent shelflife with a good glossy appearance. The outside color of fruit variesfrom 6.3R-2.5/8.9 to 6.7R-3.5/13.1 and the flesh color is mostly6.BR-3.7/15.8 to white around the core. This flesh color and internalflesh character gives a good appearance to the berry when frozen forprocessing. The aroma of the fruit is not as strong a fragrance as thatof the `Swede` variety. The seeds are small and yellow when not exposedto direct sun, mostly slightly exerted and are uniformly spaced andrelatively close to each other (not having large unprotected skinsurface areas between seeds).

Calyx: Medium to large, with the diameter of primaries reaching 50 mm,but averaging 41 mm. Individual sepals are mostly elliptical in outlineaveraging 16 in number during September with some overlapping, but mostsepals do not have serrations present. Color of sepals facing fruit is6.1GY-3.2/5.8.

                  TABLE #1                                                        ______________________________________                                        PRODUCTION AND FRUIT SIZE                                                     1993 OXNARD TIME OF PLANTING,                                                 OXNARD, CALIFORNIA                                                            ______________________________________                                                                    DIG     PLANTING                                  PLOT  VARIETY   NURSERY     DATE    DATE                                      ______________________________________                                        406   `X13`     BON         10/12/92                                                                              11/04/92                                  ______________________________________                                                     1993                                                                            MAR     APR     MAY   TOTAL                                    ______________________________________                                        NUMBER OF PICKS                                                                               6       9       6     21                                      GRAMS/PLANT    113     199     175   486                                      AVE. BERRY WT  26.4    26.4    20.4                                           (gms./berry)                                                                  ______________________________________                                                                    DIG     PLANTING                                  PLOT  VARIETY   NURSERY     DATE    DATE                                      ______________________________________                                        1209  REITER    BON         10/12/92                                                                              11/04/92                                  ______________________________________                                                     1993                                                                            MAR     APR     MAY   TOTAL                                    ______________________________________                                        NUMBER OF PICKS                                                                               7       9       6     22                                      GRAMS/PLANT    113     211     206   529                                      AVE. BERRY WT  35.4    30.7    21.2                                           (gms./berry)                                                                  ______________________________________                                         Production and size yield data is from marketable berries only. This frui     is from plants that are winter planted, and in the first year production.     Bon is a high elevation nursery.                                         

                  TABLE #2                                                        ______________________________________                                        1993 OXNARD'S TIME OF PLANTING FLAVOR                                         TEST SUMMARY                                                                  E-     # OF    LEVEL                                                          VAL-   E-      OF                                                             UA-    VAL-    SIG-                                                           TION   UA-     NIFI-    AVERAGE FLAVOR SCORE                                  DATE   TORS    CANCE    `X13` REITER CHANDLER                                 ______________________________________                                        03/22/93                                                                              8       0.009** 2.7 a 3.1 a  2.0 b                                    04/01/93                                                                             14       0.000** 3.1 a 2.8 a  2.1 b                                    04/08/93                                                                             15       0.000** 3.5 a 3.8 a  2.3 b                                    04/15/93                                                                             11      0.108    3.3   3.0    2.7                                      04/22/93                                                                             10      0.470    3.4   2.9    2.9                                      04/29/93                                                                             13       0.035*  2.9 ab                                                                              3.4 a  2.5 b                                    05/07/93                                                                             10      0.182    2.7   3.5    2.7                                      05/14/93                                                                              9      0.890    3.1   3.3    3.3                                      05/21/93                                                                              9      0.831    3.6   3.2    3.4                                      AVERAGE:        3.1     3.2      2.7                                          ______________________________________                                         **Significantly different at or below the 1% level                            *Significantly different at the 5% level                                      Panelists rated sliced portions of berries after fruit had been in cold       storage 4 to 5 days and panelists were not able to identify varieties         being rated. Flavor ratings are between 1 and 5  5 being best.           

                  TABLE #3                                                        ______________________________________                                        1992 FLY RANCH TIME OF PLANTING FLAVOR                                        TEST SUMMARY                                                                         # OF                                                                          EVAL-    LEVEL    AVERAGE FLAVOR SCORE                                 EVAL   UA-      OF             COM-                                           DATE   TORS     SIGN.    `X13` MANDER   SWEDE                                 ______________________________________                                        06/03/92                                                                             17       0.639    3.7   3.6      3.8                                   07/01/92                                                                             16        0.002** 3.6 a 2.6 b    3.5 a                                 07/15/92                                                                             12       0.341    3.0   3.5      3.3                                   07/22/92                                                                             11        0.001** 3.5 a 2.3 b    3.0 a                                 08/05/92                                                                             13       0.089    3.4   2.9      2.8                                   08/12/92                                                                             11       0.488    3.5   3.1      3.1                                   08/18/92                                                                              7       0.707    3.1   3.1      3.5                                   08/27/92                                                                             10       0.392    3.4   2.9      3.0                                   09/02/92                                                                              6       0.611    3.3   3.3      2.8                                   09/09/92                                                                             14       0.101    3.6   3.0      3.5                                   09/22/92                                                                             15        0.025*  3.5 a 2.9 b    3.5 a                                 10/07/92                                                                             11        0.001** 3.0 b 2.8 b    4.0 a                                 AVERAGE:         3.4     3.0        3.3                                       ______________________________________                                         **Significantly different at or below the 1% level                            *Significantly different at the 5% level                                      Panelists rated sliced portions of berries after fruit had been in cold       storage 4 to 5 days and panelists were not able to identify varieties         being rated. Flavor ratings are between 1 and 5  5 being best.           

                  TABLE #4                                                        ______________________________________                                        PRODUCTION AND FRUIT SIZE                                                     1993 FLY RANCH TIME OF PLANTING,                                              WATSONVILLE, CALIFORNIA                                                       ______________________________________                                                                    DIG     PLANTING                                  PLOT  VARIETY   NURSERY     DATE    DATE                                      ______________________________________                                        4205  `X13`     McA         10/19/92                                                                              11/05/92                                  ______________________________________                                                     1993                                                                            APR     MAY     JUN   JUL                                      ______________________________________                                        NUMBER OF PICKS                                                                               6       8       9     9                                       GRAMS/PLANT    103     204     228   285                                      AVE. BERRY WT  24.6    35.6    25.6  21.0                                     (gms./berry)                                                                  ______________________________________                                                     1993                                                                            AUG     SEP     OCT   TOTAL                                    ______________________________________                                        NUMBER OF PICKS                                                                               8       7       1     48                                      GRAMS/PLANT    177     255     19    1271                                     AVE. BERRY WT  21.6    21.3    21.7                                           (gms./berry)                                                                  ______________________________________                                                                    DIG     PLANTING                                  PLOT  VARIETY   NURSERY     DATE    DATE                                      ______________________________________                                        5001  SWEDE     McA         10/19/92                                                                              11/12/92                                  ______________________________________                                                     1993                                                                            APR     MAY     JUN   JUL                                      ______________________________________                                        NUMBER OF PICKS                                                                               6       8       9     9                                       GRAMS/PLANT    147     201     451   405                                      AVE. BERRY WT  27.5    40.6    31.5  23.4                                     (gms./berry)                                                                  ______________________________________                                                     1993                                                                            AUG     SEP     OCT   TOTAL                                    ______________________________________                                        NUMBER OF PICKS                                                                               9       8       1     50                                      GRAMS/PLANT    236     285     38    1763                                     AVE. BERRY WT  23.6    26.7    24.2                                           (gms./berry)                                                                  ______________________________________                                         Production and size yield data is from marketable berries only. This frui     is from plants that are winter planted and in the first year production.      McA is a high elevation nursery.                                         

                  TABLE #5                                                        ______________________________________                                        `X13` Isozyme banding patterns                                                compared to `Swede` and `Commamder` and `Joe Reiter`                          CULTIVAR     PG1         LAP    PGM                                           ______________________________________                                        `X13`        A2          B3     C4                                            `SWEDE`      A1          B3     C2                                            `COMMANDER`  A4          B3     C4                                            `JOE REITER` A4          B3     C4                                            ______________________________________                                    

                  TABLE #6                                                        ______________________________________                                        Leaf Characteristics of `X13` and `Swede`                                     Watsonville, California                                                       10/7/93                                                                                 SERRATION PETIOLE                                                             DEPTH mm* LENGTH cm**                                               ______________________________________                                        `X13`       5.1         19.0                                                  `SWEDE`     5.1         13.1                                                  ______________________________________                                         *= Measuring from serration apex to a line between where serrations join.     **= Measuring from petiolule to lowest point of basal bract.             

                  TABLE #7                                                        ______________________________________                                        AVERAGE PLANT SIZE -                                                          Watsonville, California                                                       9-17-93                                                                       Width - Leaf tip to leaf tip - centimeters                                    Height - Soil to top leaf - centimeters                                       (Plants grown over 8" plastic covering drip irrigation).                      `X13`                  `SWEDE`                                                W        H             W      H                                               ______________________________________                                        41.7      31.4         36.6   25.3                                            ______________________________________                                    

We claim:
 1. The new distinct and variety of strawberry plant hereindescribed and illustrated, and identified by the characteristicsenumerated above.